In 1900, the area along the Columbia River northeast of Portland was primarily farmland. It flooded every spring with heavy rainfall and melting mountain snows. In the dry summer and fall, water remained in shallow lakes and narrow sloughs. The land between the waterways formed great meadows surrounded by massive cottonwoods and other riparian plants.

John Charles Olmsted looked at this land with foresight. Although most considered it valueless for any other purpose than farming, he proposed acquiring a large acreage in the Columbia Slough region for future parkland. He wrote about the potential of this landscape as a contrast to the hills and river frontages in other parts of town to provide ". . . great stretches of meadow land bordered and diversified by groves of trees. No other form of park has ever proved so attractive and so useful to the masses of the people as the meadow park, particularly when there can be associated with it long reaches of still water as a landscape attraction and for boating purposes."

Olmsted proposed that Columbia Slough Park would not only provide still waters for boaters unsure of the Willamette River's strong currents, but also broad meadows for recreation such as picnicking, strolling, fast driving, horse racing (as long as gambling could be prevented), and golfing if it should retain its popularity. He suggested that the City secure hundreds to several thousand acres while this land remained inexpensive because of its regular flooding and its great distance from city development.

The land Olmsted proposed for Columbia Slough Park surrounds Switzler’s Lake. Much of this land was farmed by a family named Delminico in the early 20th century. Along with other farmers in the area, they built the original levees between 1917-1919 to reduce yearly flooding from the river. By 1920, enough families had moved into the area that an educational facility was needed for the neighborhood children. Columbia School District #33 was organized and land was purchased for a grade school and high school along NE Sixth Ave. An elementary school was built on the property located at the corner of NE Sixth and Marine Dr. The high school property one block west, which was never developed, is now the Columbia Children’s Arboretum. The Columbia School District was annexed by Faloma District #33 in 1935, then reorganized as Columbia District #33 again in 1944. Portland Public Schools finally annexed the land and school in 1964.

When Portland School District acquired Columbia School, it was designated as a middle school. The local youth who attended the school were primarily a very transient population, well below the city average in both education achievement and economic levels. In a goal to strengthen the basic curriculum through science-centered projects, Principal Bill Warner proposed a new program titled Growth through Research, Organization & Work (GROW). Students studied math, language arts, social studies, health, and science as they worked on the 28-acre site that became known as the Columbia Children’s Arboretum.

The land started out as a tangle of blackberries in 1965, but by 1970, students and families had planted 8,000 trees. Students began by planning three different scenarios for the development of the land. An orchard and organic garden was chosen for the area adjacent to NE Sixth Ave. An arboretum was designed for the land on the south side of the drainage ditch with intentions to solicit and plant trees from every U.S. state. The area furthest from Sixth Ave was planned as a natural area where indigenous plants and animals could provide a tranquil setting for study.

Before long, the creation of a garden and arboretum became a community project. Organizations of all sorts began to help the school create its dream. Edward Maddix, a Tigard architect provided construction drawings for the site. Students and staff approached the U.S. Marines for assistance with heavy land moving. Bulldozers were brought in to remove the blackberries and create a pond with an island. The Oregon Association of Nurserymen supplied trees, the Rose Society donated roses for the garden, the pond was stocked with fish by the U.S. Fish and Wildlife, the Rotary Club provided tree labels, and the list goes on. The architect worked with students to design a study shelter that was adopted by Women in Construction. Remnants of the beginning of the shelter still remain, although its construction was limited by the fact that utilities could not be brought to the site.

In 1977, Portland Public Schools built a bus barn on the site of the organic farm area. Eventually, changing demographics in northeast Portland reduced the need for Columbia Middle School, and it closed in 1983. Classes at Whitaker School, located three miles from the arboretum, adopted the GROW program in the 1980s and planting increased. However, the distance between the school and Arboretum became a problem and the program only lasted until the early 1990s. A few classrooms around the district continued to use the Arboretum for field trips. The most constant visitors were neighbors from the new housing developments on the east side of the Arboretum. The neighborhood association created a Columbia Children’s Arboretum Preservation Committee to develop goals and activities in the Arboretum. It has sponsored work parties on a monthly basis for over 10 years. In addition, the committee funded aspects of the East Columbia Wetlands Management Plan to include plans for the Arboretum site. The very first Natural Resources Management Plan in the city, it has guided development and promoted the environmental activities for the Arboretum and adjacent areas since 1988.

In 1999, Portland Parks & Recreation acquired the Columbia Children’s Arboretum land from Portland Public Schools for use as a park. Working closely with the community, a management plan for the site was developed in March 2004.